Method of dyeing textile material made of synthetic fibres

ABSTRACT

Textile material made of synthetic fibres is contacted with an aqueous dye liquor containing 20 to 50 ml. of methylene chloride per liter of dye liquor.

United States Patent 11 1 Schuierer Dec. 16, 1975 METHOD OF DYEING TEXTILE MATERIAL [56] References Cited MADE OF SYNTHETIC FIBRES UNITED STATES PATENTS Inventor: Manfred Schuierer, Z911, Germany 3,046,076 7/1962 Upshur 8/173 x 3,446,886 5/1969 Karickhoff 8/l30.l X [73] Asslgnee' g g g gg GmbH 3,616,504 11/1971 0m 8/130.1 x r ac enwa emany 3,771,954 11/1973 Kari-er 61; 51v 8/149.3 x 22 Filed; Oct. 1 73 3,771,956 12/1973 Abeta 8/174 3,776,690 12/1973 Wiatrowski ct a1. 8/94 X [21] Appl. NO.Z 405,665 3,792,977 2/1974 Guenthner 8/94 X [30] Foreign Application Priority Data Primary Examine" gjewis 1 5 Y Nov. 10,1972 Germany 2254983 Attorney Agent or lrm ars a eastmg 52 US. Cl. .I 8/174; 8/94; 8/154; ABSTRACT 2 8/175 Textile material made of synthetic fibres is contacted [51] Int. Cl. D06P 5/00; DO6P 1/90 with an aqueous dye liquor containing 20 to 50 m]. f [58] Field of Search 8/174, 175, 984,133; 1 6 8- 5: methylene chloride per liter of dye liquor.

14 Claims, N0 Drawings METHOD OF DYEING TEXTILE MATERIAL MADE OF SYNTHETIC FIBRES' BACKGROUND OF THE INVENTION This invention relates to a method of dyeing textile material made of synthetic fibres, especially of polyester, using aliphatic halogenated hydrocarbons.

In a known methodof this type (German Pat. No. 1,040,501) the textile material is passed through an aqueous solution of the dye and then heated until little or none of the water absorbed by the fibres is left. The textile material is then subjected to the saturated vapour of halogenated hydrocarbons. Since on treating the textile fabric with vapour all the halogenated hydrocarbon condensed on the fibres should be adsorbed or retained on the fibre surface, and the amount condensing is greatly increased if there is much water present on the fibres, with'the known method the textile material must be dried to a relatively large extent between the action of the aqueous solution and the treat ment with halogenated hydrocarbon vapour.

Not only does such intermediate drying involve considerable expenditure on plant, but with fabrics and knitted goods with a marked third dimension (eg with structured looped fabric) it produces the further disadvantage of a considerable migration during the intermediate drying. A final disadvantage with the known method is that the handling of relatively large amounts of halogenated hydrocarbons is necessary for the vapour treatment.

SUMMARY OF THE INVENTION The objectof the invention is thus to provide a method which avoids these disadvantages and permits very easy dyeing of textile material made of synthetic fibres.

According to the invention this object is achieved in that only those halogenated derivatives of methane, ethane and ethylene are used wherein only two H- atoms are substituted by halogens and whose boiling point is below 85C, and in that these halogenated hydrocarbons in the liquid phase are allowed to act on the textile material at the same time as the aqueous solution or dispersion of dye. i I

In the present method the intermediate drying is avoided, with all its associated disadvantages from the apparatus and dyeing technique aspects. A further advantage is that this method of operation'involves-the handling of only small amounts of halogenated hydrocarbons.

Extensive tests have shown the aliphatic halogenated hydrocarbons to be such excellent carriers that even at room temperature or at temperatures below the boiling point of the halogenated hydrocarbons they cause polyester fibres for instance to swell so much that good diffusion of dye can take place. With the method provided by the invention, dyeing can therefore take place at very low temperatures, e.g. at -50C.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method provided by the invention can be operated in a continuous, semi-continuous or discontinuous operation.

The halogenated hydrocarbons and the aqueous dye solution or dispersion can for example be applied by a continuous method to the textile material spread out in 2 web form, with the halogenated hydrocarbons forming not more than 50% of the total bath. Finally the textile material can be left in the coiledstate in a closed cham her.

For discontinuous operation the treatment of the textile material takes place in a closed container, which may for instance be under reduced pressure. In this case the halogenated hydrocarbons form less than 20% of the total dye volume.

The textile material may advantageously be subjected in the heated state to the effect of the halogenated hydrocarbons and of the aqueous dye solution or dispersion. In a semi-continuous operation, if the textile material is to be left in a heated chamber in the coiled state it may be advantageous to cause a preheated foil to run in during the coiling. It is also desirable to produce in the closed chamber a vapour pressure which corresponds to the vapour pressure of the halogenated hydrocarbon at the temperature in the chamber. In this way one avoids unwanted evaporation of the halogenated hydrocarbon, especially when the material is first placed in the chamber.

An oil-in-water emulsion is preferably formed from the halogenated hydrocarbon and the aqueous solution or dispersion of dye, however the two components can also be applied directly in sequence to the textile material, when for instance the aqueous dye solution or dispersion is first applied to the textile material, and the halogenated hydrocarbon is then applied. Naturally the reverse procedure is also possible. One of the two components can include an emulsifier.

In a particularly preferred embodiment of the invention, a large part of the dye bath consists of an inert filler material, especially a highly-iluorinated hydrocarbon, which is miscible neither with the aqueous dye solution or dispersion nor with the halogenated hydrocarbon. This filler permits operation with a very small amount of aqueous dye solution or dispersion, but with the dye nevertheless uniformly applied to the fabric. Sincethis inert filler is not contaminated, it can like the halogenated hydrocarbon be easily recovered. The composition of the dyebath of these three components (i.e. a large amount of inert fillermaterial and small amounts of the aqueous dye solution and of the halogenated hydrocarbon) is. of particular advantage, especially with a discontinuous mode of operation, because of the relatively large amount of dye bath needed in that case.

The method in accordance with the invention is illustrated more specifically by the following examples:

EXAMPLE 1 (semi-continuous operation) 256 of Resolin Blue FBL liquid 50% are first stirred with water and then water is added up to 750 ml. To

this solution is added 250 ml of methylene chloride (boiling point about 40C) in which 30g of emulsifier has previously been dissolved. A polyester fabric is dipped in the resulting emulsion, heated to 30C, and calendered to a moisture content of The dyed fabric is immediately coiled and kept for two hours in a vapour-tight chamber heated to about the same temperature. The methylene chloride is then removed by heating the fabric to 60C. After rinsing out of the unfixed residual dye an intensely blue dyed fabric is left.

EXAMPLE 2 (Discontinuous operation) A laboratory dyeing apparatus for dyeing by the extraction method is loaded with a polyester coil of 800g fabric weight. The apparatus holds altogether l of dye bath. These 10 l are prepared as follows: 40 g of Resolin Red FB liquid 50% are stirred into 9.5 l of wa ter. 500 ml of methylene chloride already containing 50g of emulsifier are emulsified into this solution. The liquor is used for dyeing 1 hour at 40C. During this time the fabric dyes deep-red, while the bath dye content drops. When dyeing has ended the bath temperature is slowly raised to 60C. The evaporated methylene chloride is condensed in a condenser. The bath freed of methylene chloride is drained. Finally the fabric is rinsed and dried.

With discontinuous operation the halogenated hydrocarbon can be added right at the start or when the dyeing temperature is reached, or else one can commence with the emulsion of hydrocarbon and water and add the aqueous dye solution or dispersion.

While in the above examples it is assumed that after completion of dyeing the recovery of the halogenated hydrocarbon is effected by distillation only, it may also be advantageous if after the dyeing the halogenated hydrocarbon with the impurities dissolved therein is separated from the aqueous phase in at least part of the dye liquor by means of mechanical separation (i.e. by utilising the different specific gravities and the non-miscibility). In this way the halogenated hydrocarbon has removed with it the fats and oligomers dissolved therein, which with recovery effected only by vapourization would readily be separated and would remain on the textile material. It will naturally be understood that in this method of mechanical separation of the halogenated hydrocarbon in the dye liquor, the halogenated hydrocarbon in the textile fabric can only be removed by heating and evaporation.

In a further beneficial form of the method provided by the invention, after completion of dyeing the dye liquor drained from the dyeing apparatus is washed in counter-flow with halogenated hydrocarbon, preferably that used for the dyeing, and this halogenated hydrocarbon is then purified by distillation. This indirect purifying method has great advantages as compared with direct mechanical or distillative purification of the aqueous liquor: while mechanical purification, especially filtration, usually gives largely unsatisfactory results, distillative purification is disadvantageous because of the volatility of many contaminants and in view of the high boiling point of water (high energy consumption).

In using methylene chloride excellent dyeing results are obtained (using, for example, l0 liters of dye liquor per kg of textile material) when 20 to 50 ml of methylene chloride (preferably 30 to 40 ml) are used per liter of dye liquor.

What I claim is:

l. A method of dyeing textile material made of synthetic fibres, comprising the step of contacting the material with an aqueous dye liquor containing 20 to 50 ml. of methylene chloride per liter of dye liquor.

2. A method according to claim- 1 wherein the material is contacted with a composition comprising a minor proportion of an aqueous dye liquor containing 20 to 50 ml. of methylene chloride per liter of dye liquor, and a major proportion of an inert liquid which is immiscible witheither the aqueous dye liquor or the methylene chloride.

3. A method according to claim 1 wherein the aqueous dye liquor contains 30 to 40 ml. of methylene chloride per liter of dye liquor.

4. A method according to claim 1 wherein the aqueous dye liquor is continuously applied to the textile material while it is spread out in web form.

5. A method according to claim 4 wherein the moistened textile material is coiled and held in a closed chamber.

6. A method according to claim 5 wherein the vapour pressure of methylene chloride in the closed chamber corresponds to the vapour pressure of methylene chloride at the temperature in the chamber.

7. A method according to claim 5 wherein a preheated foil is run in when the textile material is coiled.

8. A method according 'to claim 1 wherein the contacting is carried out at an elevated temperature.

9. A method according to claim 1 wherein the contacting is carried out as a discontinuous operation in a closed container.

10. A method according to claim 1 wherein the methylene chloride and the aqueous dye liquor are in the form of an oil-in-water emulsion.

1 l. A method according to claim 1 wherein the aqueous dye liquor applied to the textile material contains an emulsifier.

12. A method according to claim 1 wherein the remaining liquor is subsequently heated to vapourize the methylene chloride which is then recovered by condensation.

13. A method according to claim 1 wherein the methylene chloride is mechanically separated from the aqueous phase of the remaining liquor.

14. A method according to claim 1 wherein the remaining liquor is washed in counter-flow with methylene chloride, which is then purified by distillation. 

1. A METHOD OF DYEING TEXTILE MATERIAL MADE OF SYNTHETIC FIBRES, COMPRISING THE STEP OF CONTACTING THE MATERIAL WITH AN AQUEOUS DYE LIQUOR CONTAINING 20 TO 50 ML. OF METHYLENE CHLORIDE PER LITER OF DYE LIQUOR.
 2. A method according to claim 1 wherein the material is contacted with a composition comprising a minor proportion of an aqueous dye liquor containing 20 to 50 ml. of methylene chloride per liter of dye liquor, and a major proportion of an inert liquid which is immiscible with either the aqueous dye liquor or the methylene chloride.
 3. A method according to claim 1 wherein the aqueous dye liquor contains 30 to 40 ml. of methylene chloride per liter of dye liquor.
 4. A method according to claim 1 wherein the aqueous dye liquor is continuously applied to the textile material while it is spread out in web form.
 5. A method according to claim 4 wherein the moistened textile material is coiled and held in a closed chamber.
 6. A method according to claim 5 wherein the vapour pressure of methylene chloride in the closed chamber corresponds to the vapour pressure of methylene chloride at the temperature in the chamber.
 7. A method according to claim 5 wherein a preheated foil is run in when the textile material is coiled.
 8. A method according to claim 1 wherein the contacting is carried out at an elevated temperature.
 9. A method according to claim 1 wherein the contacting is carried out as a discontinuous operation in a closed container.
 10. A method according to claim 1 wherein the methylene chloride and the aqueous dye liquor are in the form of an oil-in-water emulsion.
 11. A method according to claim 1 wherein the aqueous dye liquor applied to the Textile material contains an emulsifier.
 12. A method according to claim 1 wherein the remaining liquor is subsequently heated to vapourize the methylene chloride which is then recovered by condensation.
 13. A method according to claim 1 wherein the methylene chloride is mechanically separated from the aqueous phase of the remaining liquor.
 14. A method according to claim 1 wherein the remaining liquor is washed in counter-flow with methylene chloride, which is then purified by distillation. 